I only had 3 come off contract, signed the three of them when new season kicked in.
When you resign a player, there is always a one off payment. It should go into wages, not transfers is my understanding, but I will stand corrected on that.
I've contacted support to clarify, the figure they took does not correspond with the one off payments, which is why I'm not sure if it's a bug or not. It's short by almost 100k.